The invention relates to a vehicle roof, in particular a motor vehicle roof, that is constructed sandwich-like from an outer shell and an inner shell connected to this formed as a headlining from foam plastic and produced separately from the vehicle body, which can rest with its outer edges on a bodywork frame and be firmly connected to this, wherein cavities are provided on the inner shell, said cavities being connected to the vehicle interior via grilles.
Such preproduced modular construction vehicle roofs, ready for installation, are produced separately from the vehicle body and only combined with the vehicle body on the assembly line in the production plant. In particular because of the considerable shortening of assembly times on the assembly line, these vehicle roof modules are enjoying increasing importance. These preproduced vehicle roofs can be fitted with further preassembled vehicle components such as integrated fully functioning sliding roof units, sun screens, handles, ventilation grilles, interior lights, impact-absorbing safety elements, airbags etc.
In a known vehicle roof (DE 197 09 016 A1) in the area of the outer edges of the vehicle roof intended to rest on the body frame, the inner shell is divided into two layers, the top layer of which can be placed on the vehicle frame while the lower layer is formed to bend downwards to cover the vehicle frame. With the exception of a sliding roof unit, all preassembled vehicle components are here fitted to suitable locations on the lower downwardly flexible layer of the inner shell. The cavities in the inner shell are here limited by the lower layer of inner shell. Consequently the grilles are located in the lower layer which can be bent downwards to cover the vehicle frame.
According to a proposal not previously published (DE patent application 199 51 659.6), vehicle components referred to there as function elements are also inserted releasably in the area of the inner shell not divided into two layers, in recesses formed in the foam plastic starting from the headlining surface. The cavities formed by such recesses can be formed as part of an air duct system and be covered by ventilation grilles.
According to another proposal not previously published (DE patent application 199 47 238.6) the vehicle roof consists of a rigid roof skin with a single layer inner shell foamed thereon and a headlining preformed as a separate part of foam plastic. The roof skin with foamed inner shell is here, in a manner of speaking, the outer shell of the type described initially, whereas the headlining preformed separately is consequently the inner shell. The headlining is locked releasably and interchangeably with the roof skin/inner shell. In this vehicle roof module, in the headlining, namely between the headlining and the laminate of roof skin and foamed inner shell, cavities are formed so that the invention described in more detail below is applicable similarly to this structure of roof module.
Where grilles are provided in the headlining surface of these differently structured vehicle roofs and connect cavities with the vehicle interior, these grilles are formed as separate parts and are inserted in the corresponding openings in the headlining surface during the preassembly of the roof module. Here it is difficult to structure the grilles in color and design so that they do not intrude visually in the headlining surface.
The invention is based on the task of simplifying production of the modular preproduced vehicle roofs of the type described initially with regard to design and application of grilles in the headlining surface, and in particular structuring these to be unobtrusive.
According to the present invention, there is provided a vehicle roof, in particular a motor vehicle roof, that has a sandwich-like construction including an outer shell and an inner shell connected to the outer shell formed as a headlining from foam plastic and produced separately from the vehicle body, which can rest with its outer edges on a bodywork frame and be firmly connected to the frame, wherein cavities are provided on the inner shell with grilles and wherein the grilles are formed from the foam plastic material of the inner shell itself and hence are unitary with passage openings arranged at intervals from each other, the passage openings allowing passage between the cavities and the vehicle interior.
The grilles are therefore, on formation of the inner shell of foam plastic, molded easily as one piece with the inner shell so that separate production and fitting of grilles in the vehicle roof is not required. These grilles integrated in the inner shell are relatively unobtrusive and do not disrupt the homogeneous appearance of the headlining surface facing the vehicle interior. The grilles can be provided both at cavities for air supply and/or extraction and for partial covering of interior lights fitted behind the grilles in the cavities closed by the grilles. In the latter case access to the interior lights is preferably provided outside the grilles so that where applicable the bulbs can be changed.
The passage openings can have any suitable geometric cross-section shape, preferably however they are designed as slot-like passage openings and are limited by fin-like ribs formed from the foam plastic material of the inner shell. If a light is fitted in a cavity closed by this grille, an advantageously dazzle-free and indirect interior lighting can be achieved, where the fin-like ribs influence the light emission from the cavity in the required direction. If this grille is used as a ventilation element the fin-like ribs allow air flows targeted according to their preset alignment.
To form passage openings in the foaming of the inner shell, the passage openings are first only preshaped, i.e. without wall break-through, by forming thinner wall areas at the points of the passage openings. The passage openings are then cut out subsequently. In this way the roof coating material is also applied fold-free in the preformed recesses at the points of the passage openings and is partly cut away when cutting away the thin wall areas. In this way the roof coating material extends from the visible surface of the inner shell into the passage openings so that the fin-like ribs limiting the passage openings are also largely covered with the roof coating material. The visible surface of the headlining therefore appears unobtrusive and homogeneous even at the grille points in comparison with subsequently inserted, separately produced grille structures.